1. Field of the Invention
This invention relates to fishing operations in oil wells and more particularly, to a spear assembly which is designed for use within a landing joint or sleeve and within one or more lengths of wash-over pipe to retrieve lost tools and engage and free pipe and other objects, commonly known as "fish", lodged in a well bore. The manually operated spear apparatus is characterized by a landing joint having spaced windows, which landing joint encases a spear assembly having a set of spaced lugs for engaging the windows to facilitate initial attachment of the spear assembly to the fish, disengagement of the lugs from the windows and lowering the wash-over pipe over the stationary spear assembly to "wash over" the "fish", in the well bore. The spear apparatus further includes a set of slips for selectively engaging the wash-over pipe, in order to remove the wash-over pipe, landing joint, spear assembly and "fish" from the well bore. The spear apparatus is lowered along with the landing joint and a string of wash pipe inside the well bore, by means of a conventional "fish string", which is attached to the wash-over pipe. After engagement with the "fish" by the spear apparatus is effected, rotation of the "fish string", the wash-over pipe and the landing joint to the left, for example, in the counterclockwise direction when facing the well bore, facilitates disengagement of the spaced lugs with the corresponding windows in the landing joint and continued movement of the wash-over pipe downwardly concentrically around the spear apparatus, into the well bore, to complete the "wash-over" operation. Raising of the "fish string" and the wash-over pipe facilitates engagement of the slips against the inside surface of the wash-over pipe and allows removal of the wash-over pipe, the spear apparatus and the freed "fish" from the well bore.
One of the problems which exists in the drilling of oil and gas wells is that of losing drill string and other pipe, as well as various tools, in both cased and uncased wells. The retrieval of such material from a well bore is achieved in a procedure known as a "fishing operation", in which various retrieving tools are lowered on a "fish string" to engage and retrieve the lost tools or pipe. In some cases, pipe may become stuck or jammed in the well bore by impacted sand and a procedure known as a "wash-over" operation is necessary. During the "wash-over" procedure, multiple lengths of wash-over pipe are lowered into the well bore and are forced through the well bore past the stuck pipe by using a rotary shoe and/or pumping a fluid through the well bore to wash the sand from the stuck pipe, in order to facilitate retrieval of the pipe. Various types of tools may be utilized inside the wash-over pipe, in order to engage and retrieve the stuck pipe as the wash-over pipe functions to remove the sand from the pipe and the well bore around the pipe.
2. Description of the Prior Art
An early tool which is designed for removing a casing from within a well or for removing tools which may be dropped within the casing, is detailed in U.S. Pat. No. 1,243,904, dated Oct. 23, 1917, to W. Wagner. The "Casing Spear" detailed in this patent includes a tubular carrier provided with a socket having an engaging means and gripping jaws slidably engaged within the carrier. A mandrel is also positioned within the carrier and extends within the socket, the mandrel being provided with a longitudinally-disposed slot and a transverse pin is designed to engage the gripping jaws and is loosely directed through the slot of the mandrel. An expansible member is constantly urging the pin in one direction and a breakable means coacts with the carrier and the mandrel to normally maintain the mandrel against movement under the influence of the expansible member and to normally maintain the expansible member under compression. U.S. Pat. No. 2,595,014, dated Apr. 29, 1952, to L. W. Smith, et al, details a "Hydrostatic Pulling Tool for Wells". The pulling tool is adapted to be anchored in the casing of a well bore and to pull upwardly on a "fishing tool" which is connected to the lower end of the pulling tool when the fishing tool is connected to a lodged object in the well. An "Overshot Retrieving Tool" is detailed in U.S. Pat. No. 3,393,002, dated July 16, 1968, to B. J. Woolley. The overshot retrieving tool is designed for lowering into a well casing in an unlatched condition and may be released to grasp an object with a force that increases as the weight of the object is applied to the tool. The tool is so arranged that a downward, as well as a rotational force can be applied to the object while it is being gripped. U.S. Pat. No. 4,706,745, dated Nov. 17, 1987, to Thomas R. Bishop, et al, describes a "Lock-Down Release Spear Assembly". The assembly is designed for engaging a tubular member with a tension-type spear, wherein the spear is locked to the tubular member so that it is not released when compressive or other non-tension loads are applied to it. The assembly locks the spear to the tubular member through abutment of a transfer assembly connected to the spear-supporting mandrel after the spear has been set within the tubular member. The abutment of the transfer assembly and the tubular member lock the spear within the tubular member under tension, so that compressive or other non-tension loads applied to the supporting pipe string will not affect the grip of the spear. A "Wash-over Pipe Spear Apparatus" is detailed in U.S. Pat. No. 3,747,674, dated July 24, 1973, to William K. Murray. The apparatus is designed for automatically engaging and washing-over a pipe jammed in a well bore and includes a wash-over pipe, a retrieving assembly located within the wash-over pipe having means for engaging the stuck pipe, releasable latch means joining the retrieving assembly and the wash-over pipe, so that the assembly and pipe may be lowered into position, and a slip assembly. The retrieving assembly includes a releasable clutch which selectively controls setting of the slips and may be operated by vertical manipulation of the supporting tubing string.
It is an object of this invention to provide a manually-operated spear apparatus which is capable of retrieving various pipe, tools and objects that block well bores.
Another object of the invention is to provide a new and improved, manually-operated spear assembly for location inside a landing joint and wash-over pipe connected to the landing joint, and retrieving pipe and other "fish" lodged in the bore of a well.
Still another object of this invention is to provide a manually-operated spear apparatus which includes a spear assembly having a lug mechanism and a slip assembly and a landing joint enclosing the spear assembly, wherein the lug mechanism and slip assembly can be operated in the spear assembly by rotating the landing joint, to selectively release the landing joint from the spear assembly and engage and disengage the slips with the wash-over pipe, without placing undesirable stress on the fishing string.
Another object of the invention is to provide a manually-operated spear assembly which is capable of being suspended by means of a conventional fishing string inside a landing joint with one or more sections of wash-over pipe connected to the landing joint, in order to engage one or more lengths of down-hole pipe or other "fish" which may be lodged in the bore of a well, for removing the pipe or "fish", responsive to initial vertical manipulation of the wash-over pipe and the landing joint by means of the fishing string to engage the "fish", and subsequent rotational operation of the fishing string, wash-over pipe and landing joint to effect selective engagement and disengagement of the spear assembly within the wash-over pipe and landing joint, by first lowering the wash-over pipe and landing joint with respect to the spear assembly and then lifting the wash-over pipe, landing joint, spear assembly and "fish" from the well bore.
Another object of this invention is to provide a new and improved, manually operated spear apparatus for removing an object or "fish" from a well bore, which apparatus includes a spear assembly encased in a cylindrical landing joint sleeve which is provided with three internal sleeve windows and is adapted to receive a string of wash-over pipe suspended in the well bore by a fishing string, which spear assembly includes multiple spring-loaded lugs for initially engaging the sleeve windows and maintaining the spear assembly inside the landing joint while the spear assembly is attached to the "fish", and disengaging the sleeve windows responsive to rotation of the fishing string, wash-over pipe and landing joint with respect to the spear assembly, to enable lowering of the wash-over pipe around the stationary spear assembly and the "fish" to loosen the "fish" in the well bore. Further provided is a set of slips, a pair of J-slots and a pair of J-bolts located in the spear assembly, which J-bolts are adapted to selectively engage designated leg portions in the J-slots for extending the slips into engagement with the wash-over pipe and lifting the wash-over pipe, the landing joint, the spear assembly and the "fish" from the well bore, responsive to lifting of the fishing string.